Depth finders have become an integral part of every angler’s tool set for decades. The term depth finder refers to a device utilizing sonar. Sonar emits high frequency sound waves that are inaudible to fish and humans. These impulses strike an object and reflect back to a receiver. The receiver measures the time it took for the impulses to return and continually calculates the distance between it and the object.

Raymarine Fishfinders-CHIRPSonar

Screens, graphs, or calibrated flashes display distance. The data you obtain from a depth finder screen, in part, includes: bottom composition, bottom terrain, depth, structure type and configuration, presence of fish, size of fish, and submerged weeds and wood. With the bank of information a depth finder furnishes, savvy anglers can create a complete representation of the fish’s world—a picture that will allow them to catch more fish.


Ways a depth finder enhances a fishing map:

  1. Confirming specific locations and structure – A depth finder is necessary to confirm exact locations identified on your map.
  2. Locating fish – A depth finder will tell you whether fish are present or to motor on to the next predetermined area to fish.
  3. Updating your fishing map – Navigating with a fishing map and a depth finder can improve the accuracy of your map over time.
  4. Visualizing a 3-D image – Depth finders project enough data for an angler to create a mental view of the subsurface environment.
  5. Staying on edges with fish – Weed edges and breaklines are outstanding places to catch fish and an angler must have a depth finder to stay on top of them and follow their movement.
  6. Estimating distance – Depth finders display speed and distance traveled on screen.

key west on fishidy

Looking for a GPS enabled fishing resource? The Fishidy website and the Fishidy mobile app allow you to locate fishing waterways and see species and facilities in the area.